       (let [[tag _ status] (apply-transformation {:type :transformation
                                                   :transformation
                                                   (gen-transformation "core/derive"
-                                                                      {::transformation.derive.s/newColumnTitle "Derived 7"
+                                                                      {::transformation.derive.s/newColumnTitle "Derived 8"
                                                                        ::transformation.derive.s/code "new java.util.Date()"
                                                                        ::transformation.derive.s/newColumnType "number"
                                                                        ::transformation.engine.s/onError "fail"})})]

      (let [[tag _ status] (apply-transformation {:type :transformation
                                                  :transformation
                                                  (gen-transformation "core/derive"
                                                                      {::transformation.derive.s/newColumnTitle "Derived 7"
                                                                       ::transformation.derive.s/code "quit()"
                                                                       ::transformation.derive.s/newColumnType "number"
                                                                       ::transformation.engine.s/onError "fail"})})]

                                                  ::transformation.engine.s/onError "leave-empty"})})
      (is (= ["A" "B" nil] (map :d2 (latest-data dataset-id))))

      (let [[tag _] (apply-transformation {:type :transformation
                                           :transformation
                                           (gen-transformation "core/derive"
                                                               {::transformation.derive.s/newColumnTitle "Derived 5"
                                                                ::transformation.derive.s/code "row['Derived 4'].toLowerCase()"
                                                                ::transformation.derive.s/newColumnType "text"
                                                                ::transformation.engine.s/onError "leave-empty"})})]
        (is (= tag ::lib/ok))
        (is (= ["a" "b" nil] (map :d3 (latest-data dataset-id))))))

    (testing "Date transform"
      (let [[tag res] (apply-transformation {:type :transformation
                                           :transformation
                                           (gen-transformation "core/derive"
                                                               {::transformation.derive.s/newColumnTitle "Derived 6"
                                                                ::transformation.derive.s/code "new Date()"
                                                                ::transformation.derive.s/newColumnType "date"
                                                                ::transformation.engine.s/onError "fail"})})]
        (is (= tag ::lib/ok))
        (is (every? number? (map :d4 (latest-data dataset-id))))))


    (testing "derive to number column"
      (let [[tag res] (apply-transformation {:type :transformation
                                             :transformation
                                             (gen-transformation "core/derive"
                                                                 {::transformation.derive.s/newColumnTitle "Derived 7"
                                                                  ::transformation.derive.s/code "row.bar"
                                                                  ::transformation.derive.s/newColumnType "number"
                                                                  ::transformation.engine.s/onError "fail"})})]
        (is (= tag ::lib/ok))
        (is (every? number? (map :d5 (latest-data dataset-id))))))


 
 
    (testing "Valid type check"
      (let [[tag _ status] (apply-transformation {:type :transformation
                                                  :transformation
                                                  (gen-transformation "core/derive"
                                                                      {::transformation.derive.s/newColumnTitle "Derived 8"
                                                                       ::transformation.derive.s/code "new Date()"
                                                                       ::transformation.derive.s/newColumnType "number"
                                                                       ::transformation.engine.s/onError "fail"})})]
